A Proposed Structure of a Bacterial Membrane Protein Shows That

question 51

Multiple Choice

A proposed structure of a bacterial membrane protein shows that the distance between successive amino acids in a region crossing the membrane is 3.4 Å.Recall that a typical lipid bilayer is approximately 40 Å across.Which of the following is the most likely description of the protein?

• A) The transmembrane region of the protein resembles the transmembrane region of the Ca²⁺-ATPase transporter protein.
• B) The primary sequence of the transmembrane region of the protein is composed of approximately nine amino acids.
• C) The protein contains a selectivity channel.
• D) The protein resembles a porin.

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Definitions:

Bond Dipole Moment

A measure of the inequality in the electron distribution between two atoms in a bond, leading to a polar molecule if present across the molecule.

Methanol

The simplest alcohol, with the formula CH3OH, used as a solvent, antifreeze, fuel, and as a precursor to other chemicals.

C-O Bond

The covalent bond formed between a carbon and an oxygen atom, a fundamental bond in organic chemistry.

Molecular Dipole Moment

A measure of the separation of positive and negative electrical charges within a molecule, affecting its polarity and interactions with other molecules.